Explainer: What to know about US election day

An American flag flies in the wind as a voter leaves a polling site after casting a ballot in Dearborn, Michigan Picture: David Goldman/AP

Polls opened in the US on Tuesday and Americans across the country are casting their ballots in the 2024 presidential election.

In a deeply divided nation, the election between Democrat Kamala Harris and Republican Donald Trump is one of the closest presidential races in history.